Effects of Weather Presentation Symbology on General Aviation Pilot Behavior, Workload and Visual Scanning

Objective: The purpose of this study is to explore the effects of cockpit weather presentation symbology on General Aviation (GA) pilot weather avoidance, weather presentation usage, and cognitive workload. Background: To support the Next Generation Air Transportation System (NextGen) program, on-going efforts focus on the implementation and use of weather technologies and weather presentations. Currently, there are no Federal Aviation Administration (FAA) or industry standards for the presentation of weather information in the cockpit. Method: Twenty-five instrument-rated GA pilots were randomly allocated to one of three simulation groups. During two 25-minute simulation flights, participants flew a Cessna 172 single-engine GA aircraft (using autopilot) under Visual Meteorological Conditions (VMC) and Instrument Meteorological Conditions (IMC). The pilots had to avoid the weather by using the cockpit weather presentation. We manipulated the cockpit weather presentation so that each pilot group used a different weather presentation symbology. Results: We found group differences in weather deviations, visual scanning behavior, and cognitive workload. Conclusions: Variations in weather presentations (colors and symbology) seem to affect pilot behavior and decision-making. Applications: This simulation is part of an on-going assessment of the effects of weather presentation symbology related to the standardization and optimization of weather presentations in cockpits

Initial Assessment of Portable Weather Presentations for General Aviation Pilots

Objective: (a) To examine the potential benefits and effect on pilot flying behavior from the use of portable weather presentations and (b) to assess pilot sensitivity to weather symbology changes. Method: Seventy-three General Aviation (GA) pilots volunteered to participate in the study. During simulated flights, participants were randomly assigned either to an experimental group or to a control group and flew a simulated single-engine GA aircraft under Visual Flight Rules (VFR) while avoiding hazardous weather. The experimental group was equipped with a portable “weather application” during flight. We recorded flight profile parameters, Weather Situation Awareness (WSA), decision-making, cognitive engagement, weather-application interaction, and aircraft distance-to-weather. Using a change-detection experiment, we assessed participants’ sensitivity to symbology changes in portable weather presentations. Results: We found positive effects from the use of the portable weather application with an increased WSA for the experimental group. This resulted in credibly larger route deviations and credibly greater distances to hazardous weather (≥ 30 dBZ cells) in the experimental group than in the control group. Nevertheless, both groups flew too closely to hazardous weather compared to what is recommended in current Federal Aviation Administration guidelines. We also found a credibly higher cognitive engagement (prefrontal oxygenation levels) for the experimental group, possibly reflecting increased flight planning and decision-making among the participants. Using a change-detection experiment, we assessed participant discriminability of signal and noise trials using cloud ceiling, precipitation, and PIREP information. We found that discrimination performance was low for all conditions in comparison to the performance of a group of ideal observers as measured by the signal detection (SD) metric for discriminability (d). Conclusion: The study outcome supports our hypothesis that the portable weather application can be used without degrading pilot performance on safety-related flight tasks, actions, and decisions. However, it also shows that an increased WSA does not automatically transfer over to improved flight behavior. The outcome shows that participants could learn and operate the portable weather application with relative ease, but training is necessary to help pilots translate weather information into improved flight-behavior strategies. The outcome from the change-detection experiment shows that work is still needed to optimize the symbology for portable cockpit weather presentations. Applications: This simulation is part of an initial assessment of the effects of portable weather applications on pilot behavior and decision-making

The Effect of Weather State-Change Notifications on General Aviation Pilots' Behavior, Cognitive Engagement, and Weather Situation Awareness

Objective: Results from the WTIC Phase 2 study showed that general aviation (GA) pilots performed poorly at detecting aviation routine weather report (METAR) symbol changes during flight (Ahlstrom & Suss, 2014)—attributed to the change-blindness phenomena. Here, we address this gap by examining the potential benefits of weather state-change notifications on pilots’ behavior and Weather Situation Awareness (WSA) during a simulated flight. A second objective of this study was to assess pilot sensitivity to weather symbology changes on Topological, Visual Flight Rules (VFR), and Instrument Flight Rules (IFR) aeronautical map backgrounds in a change-detection experiment. Method: Seventy-three GA pilots volunteered to participate in the study. During a simulated weather scenario, participants were randomly assigned to an experimental or a control group and flew a single-engine GA aircraft, initially under Visual Meteorological Conditions (VMC). The experimental group was equipped with a vibrating bracelet that notified participants of state-changes to displayed METAR, Special-Use Airspace (SUA), and Significant Meteorological Information (SIGMET) symbols. During the simulation, we recorded each participant’s horizontal and vertical flight profile, WSA, decision-making, cognitive engagement, weather presentation interaction, and distance from the aircraft to hazardous weather. Finally, we used a change-detection experiment to assess participant sensitivity to changes in weather symbols on three different backgrounds. Results: By assessing WSA, we found that the experimental group provided credibly more communications of weather information and maneuver/course change information and a higher number of “out-the-window” reports to the pilot following than the control group provided. This supports our hypothesis that weather state-change notifications result in earlier and more accurate recognition of weather state-changes and, thereby, positively improves participant WSA. The results of distance-to-weather analyses showed that both groups kept similar distances to 30 dBZ precipitation cells. It also showed, however, that participants in both groups flew closer to hazardous weather than what is recommended in current guidelines. Although not a credible difference, there were more participant reports of VFR flights into Instrument Meteorological Conditions (IMC) in the control group (N = 33) than in the experimental group (N = 27). When analyzing the functional near-infrared (fNIR) data, we found credibly higher prefrontal oxygenation levels in the control group compared to the experimental group. We attribute the reduced cognitive load in the experimental group to increased participant WSA. Because of the state-change notifications, participants were more attentive to information on the weather presentation, which enhanced planning and decision-making and reduced cognitive load. Finally, participant discrimination performance for symbol changes was low on the Topological, IFR, and VFR map backgrounds when compared to the performance of a simulated group of ideal observers. We interpret these findings to indicate that much work is still needed to optimize the symbology for cockpit weather presentations to achieve good symbol discrimination and reduce the time needed to differentiate weather presentation elements on all backgrounds. Conclusion: Weather state-change notifications improved WSA and reduced cognitive workload. However, these improvements did not translate to changes in participants’ weather-avoiding behavior, indicating gaps in pilot understanding of the information or gaps in pilot decision making. Applications: This simulation is part of an ongoing assessment of the effects of weather-presentation symbology related to the optimization of weather presentations in cockpits